This be high current power supply circuit , Which there is the size voltage 13.8V at 20A.By it uses base equipment that seeks to buy easy, be integrated number circuit LM741 perform maintain one’s position voltage be stable or Regulated at 13.8V. Which can fine can decorate a little again. Besides still have the power transistors 2N3055 X4 numbers bring to build parallel perform enlarge current tall arrive at 20Amp Other detail , see in the circuit.